Narrative:

During takeoff as the wheels lifted off; we got a chime with a look up light. We ignored the chime until we got through the after takeoff checklist. Once that was complete; we assessed the situation. The first thing we noticed was that the first officer's easi/HSI screens were black. Once we looked up at the electrical panel; the right main bus and right ess bus lights were illuminated. Upon identifying the electrical failure; we also noticed several other components and systems affected. We had lost the WX radar; the autopilot and yaw damper; the GPS; the TCAS; communication 2 and navigation 2; and propeller indication (np) on the right engine. Since there was convective activity in the area; we decided to return to ZZZ without the WX radar. While being vectored back for an approach; we ran the QRH electrics checklist. Once that was completed; we were under way being vectored for an ILS to runway 18R. As we got closer to the airport; the first officer noticed that our main accumulator pressure was reading 0. He then mentioned that we may have a gear indication issue as well. I then called for 'gear down.' it felt like the gear came down; but we did not get the three green 'locked down' indication. Not wanting to land with an uncertain gear indication; we broke off the approach; declared an emergency and asked for delay vectors to run more checklists. At this point; we went to the QRH hydraulics checklist; and started running through it. As we started going through the checklist; we soon realized that this was not a hydraulic issue. We did not have a hydraulic look down light; so we went back to the QRH electrics checklist. Upon referencing the electrical distribution list for the right ess bus; we realized that we had lost the landing gear down lock indications (three green). I also called back to the flight attendant to look to see if the gear were down. She said it appeared that both mains were down. Now we decided to put the electrics problem on the back burner and focus on whether or not the gear was down and locked. I asked permission from ATC to leave the frequency to contact dispatch and maintenance control. After contacting dispatch; and advising them of our situation; I contacted maintenance. My biggest question was whether or not the gear was locked down and if there was any way that I could tell for sure. Maintenance told me that if the gear handle was down; the transit lights were not illuminated; and the hydraulic pump was not running; that I could assume the gear was down and locked. Once returning to ATC; we requested vectors for the approach and made sure that the trucks were standing by. I talked to the flight attendant; and told her that the landing should be normal; but there was no way to tell for sure. She decided that she would have the passenger brace upon landing just to be safe. I also spoke to the passenger and let them know of the situation and that the fire trucks would be standing by. We landed the aircraft without incident; and were able to exit the runway. However; upon exiting; the nosewheel steering was not operating normally. I then decided to situation and wait for a tug.callback conversation with reporter acn 745277 revealed the following information: both generators continued to operate normally and the bus circuit breaker's were not popped. No reason could be found why the right main and right ess busses had failed at liftoff. While waiting for tow in after landing; the right main bus circuit breaker was pulled and reset which restored full electrical power.

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Original NASA ASRS Text

Title: SF340 FLT CREW REPORTS R MAIN AND R ESS BUS FAILURES AT LIFTOFF WITH BOTH GENERATORS OPERATING NORMALLY.

Narrative: DURING TAKEOFF AS THE WHEELS LIFTED OFF; WE GOT A CHIME WITH A LOOK UP LIGHT. WE IGNORED THE CHIME UNTIL WE GOT THROUGH THE AFTER TAKEOFF CHECKLIST. ONCE THAT WAS COMPLETE; WE ASSESSED THE SITUATION. THE FIRST THING WE NOTICED WAS THAT THE FO'S EASI/HSI SCREENS WERE BLACK. ONCE WE LOOKED UP AT THE ELECTRICAL PANEL; THE R MAIN BUS AND R ESS BUS LIGHTS WERE ILLUMINATED. UPON IDENTIFYING THE ELECTRICAL FAILURE; WE ALSO NOTICED SEVERAL OTHER COMPONENTS AND SYSTEMS AFFECTED. WE HAD LOST THE WX RADAR; THE AUTOPILOT AND YAW DAMPER; THE GPS; THE TCAS; COM 2 AND NAV 2; AND PROP INDICATION (NP) ON THE R ENGINE. SINCE THERE WAS CONVECTIVE ACTIVITY IN THE AREA; WE DECIDED TO RETURN TO ZZZ WITHOUT THE WX RADAR. WHILE BEING VECTORED BACK FOR AN APCH; WE RAN THE QRH ELECTRICS CHECKLIST. ONCE THAT WAS COMPLETED; WE WERE UNDER WAY BEING VECTORED FOR AN ILS TO RWY 18R. AS WE GOT CLOSER TO THE ARPT; THE FO NOTICED THAT OUR MAIN ACCUMULATOR PRESSURE WAS READING 0. HE THEN MENTIONED THAT WE MAY HAVE A GEAR INDICATION ISSUE AS WELL. I THEN CALLED FOR 'GEAR DOWN.' IT FELT LIKE THE GEAR CAME DOWN; BUT WE DID NOT GET THE THREE GREEN 'LOCKED DOWN' INDICATION. NOT WANTING TO LAND WITH AN UNCERTAIN GEAR INDICATION; WE BROKE OFF THE APCH; DECLARED AN EMER AND ASKED FOR DELAY VECTORS TO RUN MORE CHECKLISTS. AT THIS POINT; WE WENT TO THE QRH HYDRAULICS CHECKLIST; AND STARTED RUNNING THROUGH IT. AS WE STARTED GOING THROUGH THE CHECKLIST; WE SOON REALIZED THAT THIS WAS NOT A HYDRAULIC ISSUE. WE DID NOT HAVE A HYD LOOK DOWN LIGHT; SO WE WENT BACK TO THE QRH ELECTRICS CHECKLIST. UPON REFERENCING THE ELECTRICAL DISTRIBUTION LIST FOR THE R ESS BUS; WE REALIZED THAT WE HAD LOST THE LNDG GEAR DOWN LOCK INDICATIONS (THREE GREEN). I ALSO CALLED BACK TO THE FLIGHT ATTENDANT TO LOOK TO SEE IF THE GEAR WERE DOWN. SHE SAID IT APPEARED THAT BOTH MAINS WERE DOWN. NOW WE DECIDED TO PUT THE ELECTRICS PROBLEM ON THE BACK BURNER AND FOCUS ON WHETHER OR NOT THE GEAR WAS DOWN AND LOCKED. I ASKED PERMISSION FROM ATC TO LEAVE THE FREQUENCY TO CONTACT DISPATCH AND MAINT CTL. AFTER CONTACTING DISPATCH; AND ADVISING THEM OF OUR SITUATION; I CONTACTED MAINT. MY BIGGEST QUESTION WAS WHETHER OR NOT THE GEAR WAS LOCKED DOWN AND IF THERE WAS ANY WAY THAT I COULD TELL FOR SURE. MAINT TOLD ME THAT IF THE GEAR HANDLE WAS DOWN; THE TRANSIT LIGHTS WERE NOT ILLUMINATED; AND THE HYDRAULIC PUMP WAS NOT RUNNING; THAT I COULD ASSUME THE GEAR WAS DOWN AND LOCKED. ONCE RETURNING TO ATC; WE REQUESTED VECTORS FOR THE APCH AND MADE SURE THAT THE TRUCKS WERE STANDING BY. I TALKED TO THE FLIGHT ATTENDANT; AND TOLD HER THAT THE LANDING SHOULD BE NORMAL; BUT THERE WAS NO WAY TO TELL FOR SURE. SHE DECIDED THAT SHE WOULD HAVE THE PAX BRACE UPON LNDG JUST TO BE SAFE. I ALSO SPOKE TO THE PAX AND LET THEM KNOW OF THE SITUATION AND THAT THE FIRE TRUCKS WOULD BE STANDING BY. WE LANDED THE ACFT WITHOUT INCIDENT; AND WERE ABLE TO EXIT THE RWY. HOWEVER; UPON EXITING; THE NOSEWHEEL STEERING WAS NOT OPERATING NORMALLY. I THEN DECIDED TO SIT AND WAIT FOR A TUG.CALLBACK CONVERSATION WITH RPTR ACN 745277 REVEALED THE FOLLOWING INFO: BOTH GENERATORS CONTINUED TO OPERATE NORMALLY AND THE BUS CB'S WERE NOT POPPED. NO REASON COULD BE FOUND WHY THE R MAIN AND R ESS BUSSES HAD FAILED AT LIFTOFF. WHILE WAITING FOR TOW IN AFTER LNDG; THE R MAIN BUS CB WAS PULLED AND RESET WHICH RESTORED FULL ELECTRICAL POWER.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.